As BT were unable to help sort out the problem of continual compromising of my account, failing to call me back when promised and the rest of it, I had a go at solving things myself. I mentioned this in the original thread but it has not been picked up so worth posting a new thread on.
I began moving my emails to gmail, and lo and behold once I had moved a particular mailing list hosted via groups.io the problems of constantly having to reset my password due to possible account security breeches stopped - it has now been a week and touch wood everything has been fine since. This may be worth noting as a solution for future occurences.
I am sure it cannot just be me who has been affected, and no thanks to BT for being utterly useless and wasting huge amounts of my time waiting in for calls that never happened.